A cloud data center is a data center that provides access to virtualized applications, services, and data storage to off-premises customers. In a typical cloud data center environment, there is a large collection of interconnected servers that provide computing (e.g., compute nodes) and/or storage capacity to run various applications. For example, a cloud data center comprises a facility that hosts virtualized applications and services for customers of the cloud data center. The cloud data center for example, hosts all the infrastructure equipment, such as networking and storage systems, redundant power supplies, and environmental controls. In a typical cloud data center, clusters of storage systems and application servers are interconnected via high-speed switch fabric provided by one or more tiers of physical network switches and routers. More sophisticated cloud data centers provide infrastructure spread throughout the world with subscriber support equipment located in various physical hosting facilities.
Software Defined Networking (SDN) platforms may be used in cloud data centers, and in some cases, may use a logically centralized and physically distributed SDN controller, and a distributed forwarding plane in virtual routers that extend the network from physical routers and switches in the cloud data center into a virtual overlay network hosted in virtualized servers. The SDN controller provides management, control, and analytics functions of a virtualized network and orchestrates the virtual routers by communicating with the virtual routers.